PAUL Anthony Rogers had the names of his loved ones tattooed on his body in a display of admiration and love for his daughter, son and then fiancée.

But at his own hands, two of those loved ones are now dead.

Police were shaken by the discovery at 9.30pm on Monday of the bodies of Mr Rogers and his five year-old daughter Kyla in a car partly hidden in roadside scrub 30 metres off the Bruxner Highway at Piora, west of Casino.

Richmond Local Area Commander Superintendent Greg Martin said it was apparent the man and girl had died from carbon monoxide poisoning. The bodies will undergo autopsy in Brisbane and a report will be prepared for the Queensland Coroner.

A member of the public first sighted the car at 10.30am, but only reported it to police after matching its description to details in an abduction alert issued by Queensland Police at 3.15pm on Monday.

Police defended their decision to issue the alert eight hours after they knew Kyla was missing.

“You have to weigh up that you may tip off this person you are after and they may do something that is tragic, which was the case ... but we were not to know that,” Supt Martin said.

The tragic discovery was a devastating end to an interstate hunt for Mr Rogers and Kyla after the double murder of Kyla's mother Tania Simpson, 31, and family friend Antony Way, 33, at a Robina unit on the Gold Coast early on Monday.

Police allege Mr Rogers abducted Kyla from the unit after she slept through the murders. They believe Mr Rogers drove immediately to Piora before gassing himself and Kyla in the car.

Kyla's 20-month-old brother, now an orphan, escaped unharmed after he stayed with his grandparents on the night of the murders.

Mr Rogers and Ms Simpson lived in Inverell last year where they managed the Fossickers Rest Caravan Park, purchased by Ms Simpson's father.

Police do not know why Mr Rogers chose to end his own life and that of his daughter on the side of the rural highway.

One person who spoke to The Northern Star believed Mr Rogers and Ms Simpson could have once resided in the Mummulgum or Casino area, but police said there was no evidence to support the claim.

The NZ Press reported the second murder victim, Antony Way, and Mr Rogers were both originally from that country.

Casino resident and father of two daughters Ashley Rankin laid flowers for Kyla at the site of her death in Piora yesterday while police conducted a search of the area for further evidence.

Kyla Rogers' name was initially reported as Kayla Rogers by police, which was incorrect.